// See License comments in shader string

(function(Blotter, _) {

  Blotter.Assets.Shaders.Noise3D = [
    "//",
    "// Description : Array and textureless GLSL 2D/3D/4D simplex",
    "//               noise functions.",
    "//      Author : Ian McEwan, Ashima Arts.",
    "//  Maintainer : ijm",
    "//     Lastmod : 20110822 (ijm)",
    "//     License : Copyright (C) 2011 Ashima Arts. All rights reserved.",
    "//               Distributed under the MIT License. See LICENSE file.",
    "//               https://github.com/ashima/webgl-noise",
    "//",
    "",
    "vec2 n3mod289(vec2 x) {",
    "  return x - floor(x * (1.0 / 289.0)) * 289.0;",
    "}",
    "",
    "vec3 n3mod289(vec3 x) {",
    "  return x - floor(x * (1.0 / 289.0)) * 289.0;",
    "}",
    "",
    "vec4 n3mod289(vec4 x) {",
    "  return x - floor(x * (1.0 / 289.0)) * 289.0;",
    "}",
    "",
    "vec4 permute(vec4 x) {",
    "     return n3mod289(((x*34.0)+1.0)*x);",
    "}",
    "",
    "vec4 taylorInvSqrt(vec4 r)",
    "{",
    "  return 1.79284291400159 - 0.85373472095314 * r;",
    "}",
    "",
    "float snoise(vec3 v)",
    "  {",
    "  const vec2  C = vec2(1.0/6.0, 1.0/3.0) ;",
    "  const vec4  D = vec4(0.0, 0.5, 1.0, 2.0);",
    "",
    "// First corner",
    "  vec3 i  = floor(v + dot(v, C.yyy) );",
    "  vec3 x0 =   v - i + dot(i, C.xxx) ;",
    "",
    "// Other corners",
    "  vec3 g = step(x0.yzx, x0.xyz);",
    "  vec3 l = 1.0 - g;",
    "  vec3 i1 = min( g.xyz, l.zxy );",
    "  vec3 i2 = max( g.xyz, l.zxy );",
    "",
    "  //   x0 = x0 - 0.0 + 0.0 * C.xxx;",
    "  //   x1 = x0 - i1  + 1.0 * C.xxx;",
    "  //   x2 = x0 - i2  + 2.0 * C.xxx;",
    "  //   x3 = x0 - 1.0 + 3.0 * C.xxx;",
    "  vec3 x1 = x0 - i1 + C.xxx;",
    "  vec3 x2 = x0 - i2 + C.yyy; // 2.0*C.x = 1/3 = C.y",
    "  vec3 x3 = x0 - D.yyy;      // -1.0+3.0*C.x = -0.5 = -D.y",
    "",
    "// Permutations",
    "  i = n3mod289(i);",
    "  vec4 p = permute( permute( permute(",
    "             i.z + vec4(0.0, i1.z, i2.z, 1.0 ))",
    "           + i.y + vec4(0.0, i1.y, i2.y, 1.0 ))",
    "           + i.x + vec4(0.0, i1.x, i2.x, 1.0 ));",
    "",
    "// Gradients: 7x7 points over a square, mapped onto an octahedron.",
    "// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)",
    "  float n_ = 0.142857142857; // 1.0/7.0",
    "  vec3  ns = n_ * D.wyz - D.xzx;",
    "",
    "  vec4 j = p - 49.0 * floor(p * ns.z * ns.z);  //  mod(p,7*7)",
    "",
    "  vec4 x_ = floor(j * ns.z);",
    "  vec4 y_ = floor(j - 7.0 * x_ );    // mod(j,N)",
    "",
    "  vec4 x = x_ *ns.x + ns.yyyy;",
    "  vec4 y = y_ *ns.x + ns.yyyy;",
    "  vec4 h = 1.0 - abs(x) - abs(y);",
    "",
    "  vec4 b0 = vec4( x.xy, y.xy );",
    "  vec4 b1 = vec4( x.zw, y.zw );",
    "",
    "  //vec4 s0 = vec4(lessThan(b0,0.0))*2.0 - 1.0;",
    "  //vec4 s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0;",
    "  vec4 s0 = floor(b0)*2.0 + 1.0;",
    "  vec4 s1 = floor(b1)*2.0 + 1.0;",
    "  vec4 sh = -step(h, vec4(0.0));",
    "",
    "  vec4 a0 = b0.xzyw + s0.xzyw*sh.xxyy ;",
    "  vec4 a1 = b1.xzyw + s1.xzyw*sh.zzww ;",
    "",
    "  vec3 p0 = vec3(a0.xy,h.x);",
    "  vec3 p1 = vec3(a0.zw,h.y);",
    "  vec3 p2 = vec3(a1.xy,h.z);",
    "  vec3 p3 = vec3(a1.zw,h.w);",
    "",
    "//Normalise gradients",
    "  vec4 norm = taylorInvSqrt(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3)));",
    "  p0 *= norm.x;",
    "  p1 *= norm.y;",
    "  p2 *= norm.z;",
    "  p3 *= norm.w;",
    "",
    "// Mix final noise value",
    "  vec4 m = max(0.6 - vec4(dot(x0,x0), dot(x1,x1), dot(x2,x2), dot(x3,x3)), 0.0);",
    "  m = m * m;",
    "  return 42.0 * dot( m*m, vec4( dot(p0,x0), dot(p1,x1),",
    "                                dot(p2,x2), dot(p3,x3) ) );",
    "  }"
  ].join("\n");

})(
  this.Blotter, this._
);
